Dual lens camera unit

ABSTRACT

Embodiments of the invention relate to a portable digital video system sized to be worn on the user&#39;s body and equipped with a plurality of lens assemblies for recording video in a plurality of directions. In one embodiment, the invention includes a camera unit comprising a first lens assembly, a second lens assembly, a first housing containing the first lens assembly and the second lens assembly, a battery unit, a first storage memory, controller circuitry operable to receive video data from the first lens assembly and the second lens assembly and store the video data in the first storage memory, and a second housing containing the battery unit and attached via a cable to the first housing unit. In some embodiments, the system is equipped with both volatile and non-volatile memory for continuous recording with permanent storage of key video segments.

RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 14/517,226, filed Oct. 17, 2014, which is a continuation-in-part application U.S. patent application Ser. No. 13/967,151, filed Aug. 14, 2013, now U.S. Pat. No. 9,2533,452, the disclosures of which are incorporated herein by reference in their entirety into the present application.

Embodiments and/or features of the invention described in the present document may be used with the subject matter disclosed in commonly assigned U.S. Pat. No. 8,781,292, filed Sep. 27, 2013, issued Jul. 15, 2014, and entitled “COMPUTER PROGRAM, METHOD, AND SYSTEM FOR MANAGING MULTIPLE DATA RECORDING DEVICES” (“the '292 Patent”), which is a continuation application of the '151 Application. The '292 Patent is hereby incorporated by reference in its entirety into the present application.

Embodiments and/or features of the invention described in the present document may be used with the subject matter disclosed in commonly assigned U.S. patent application Ser. No. 14/040,329, filed Sep. 27, 2013, and entitled “PORTABLE VIDEO AND IMAGING SYSTEM” (“the '329 Application”); and commonly assigned U.S. patent application Ser. No. 14/040,006, filed Sep. 27, 2013, and entitled “MOBILE VIDEO AND IMAGING SYSTEM” (“the '006 Application”). The '329 Application and the '006 Application are hereby incorporated by reference in their entirety into the present application.

Further, embodiments and/or features of the invention described in the present document may be used with the subject matter disclosed in commonly assigned and concurrently filed U.S. patent application Ser. No. 14/517,368 filed Oct. 17, 2014, and entitled “FORENSIC VIDEO RECORDING WITH PRESENCE DETECTION,” and with concurrently filed and commonly assigned U.S. patent application Ser. No. 14/517,160 filed Oct. 17, 2014, and entitled “BREATH ANALYZER, SYSTEM, AND COMPUTER PROGRAM FOR AUTHENTICATING, PRESERVING, AND PRESENTING BREATH ANALYSIS DATA.” Each of the concurrently filed patent applications is also a continuation-in-part of the '151 Application. The concurrently filed patent applications are hereby incorporated by reference in their entirety into the present application.

BACKGROUND 1. Field

Embodiments of the invention relate to a multi-lens camera unit for recording video images. More particularly, embodiments of the invention relate to a portable digital video system sized to be worn on the user's body and equipped with a plurality of lens assemblies for recording video in a plurality of directions.

2. Related Art

There is a need for wearable video recording devices for purposes such as law enforcement, as prior devices are limited to capturing video in a single direction. Thus, in the case of a head-mounted unit, events occurring behind and to a side of the user are not recorded.

SUMMARY

Embodiments of the invention solve the above problem by providing an apparatus and method for a wearably sized, multi-lens digital recorder. In a first embodiment, the invention includes a camera unit comprising a first lens assembly, a second lens assembly, a first housing containing the first lens assembly and the second lens assembly, a battery unit, a first storage memory, controller circuitry operable to receive video data from the first lens assembly and the second lens assembly and store the video data in the first storage memory, and a second housing containing the battery unit and attached via a cable to the first housing unit.

A second embodiment includes a method of controlling the operation of a camera unit comprising the steps of storing imagery from a first lens assembly and a nonparaxial second lens assembly to a first storage memory, receiving a trigger signal in response to a trigger event, transferring an imagery from the first storage memory to a second storage memory, and in response to the trigger signal, storing imagery from the first lens assembly and the second lens assembly to the second storage memory.

A third embodiment of the invention includes a dual-lens camera apparatus, comprising a camera housing including a plurality of non-paraxial lens assemblies, a battery housing connected by a cable to the camera housing and providing power thereto, a volatile memory, and a non-volatile memory.

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other aspects and advantages of the current invention will be apparent from the following detailed description of the embodiments and the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 depicts a system diagram showing the components of one embodiment of the invention;

FIGS. 2(a) and 2(b) depict a first and second view of one embodiment of the invention with the lenses fixedly mounted in a reciprocal orientation;

FIGS. 3(a)-3(c) depict a first and a second view of another embodiment of the invention with the lenses rotatably mounted and shown in a skew orientation;

FIGS. 4(a)-4(c) depict a variety of exemplary lens orientations; and

FIG. 5 depicts a flowchart illustrating the operation of one embodiment of the invention.

The drawing figures do not limit the invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.

DETAILED DESCRIPTION

The subject matter of embodiments of the invention is described in detail below to meet statutory requirements; however, the description itself is not intended to limit the scope of claims. Rather, the claimed subject matter might be embodied in other ways to include different steps or combinations of steps similar to the ones described in this document, in conjunction with other present or future technologies. Minor variations from the description below will be obvious to one skilled in the art and are intended to be captured within the scope of the claimed invention. Terms should not be interpreted as implying any particular ordering of various steps described unless the order of individual steps is explicitly described.

The following detailed description of embodiments of the invention references the accompanying drawings that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of embodiments of the invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.

In this description, references to “one embodiment,” “an embodiment,” or “embodiments,” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate reference to “one embodiment,” “an embodiment,” or “embodiments,” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, or act described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the technology can include a variety of combinations and/or integrations of the embodiments described herein.

Embodiments of the invention may be embodied as, among other subject matter, a method, a system, or a set of instructions embodied on one or more computer-readable media. Computer-readable media include both volatile and nonvolatile media, removable and nonremovable media, and contemplate media readable by a database. For example, computer-readable media include (but are not limited to) RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile discs (DVD), holographic media or other optical disc storage, magnetic cassettes, magnetic tape, magnetic disk storage, and other magnetic storage devices. These technologies can store data temporarily or permanently. However, unless explicitly specified otherwise, the term “computer-readable media” should not be construed to include physical, but transitory, forms of signal transmission such as radio broadcasts, electrical signals through a wire, or light pulses through a fiber-optic cable. Examples of stored information include computer-useable instructions, data structures, program modules, and other data representations.

Different forms of computer-readable media store data in different ways. For example, volatile storage media such as RAM may retain data only as long as it is powered, while non-volatile media such as flash memory retain data even when powered off. Furthermore, some forms of computer storage media are write-once, read many (WORM), such that data can be stored to them but not erased or overwritten. For some forms of WORM media, data can be recorded in multiple sessions, where the data from one session is appended to the data from the previous session. Other forms of media may be indefinitely rewriteable. Some forms of media may be encrypted, such that data is written to them encrypted by an encryption key (which can correspond to the device, the user, or be unique in some other way) and data read from them is scrambled unless decrypted with the corresponding decryption key.

Additionally, storage media can be made tamper-resistant such that it is difficult or impossible to alter or erase data stored to them, or to prevent reading data except by authorized means. WORM media or encrypted media, as described above are one way to make storage media tamper resistant. Another way is to make storage media physically difficult to remove, such as by covering them with epoxy after they have been installed. Other methods of making storage resistant tamper resistant are also known in the art and can be used.

Turning first to FIG. 1, a system diagram showing the components of one embodiment of the invention is depicted. In some embodiments, lens housing 100 is a streamlined, miniature shape as depicted in FIGS. 2 and 3. In some embodiments, lens housing 100 is less than or equal to ten inches long. In other embodiments, lens housing 100 measures less than or equal to six inches in length. In still other embodiments, lens housing 100 measures less than or equal to four inches in length. In yet other embodiments, lens housing 100 measures less than or equal to two inches long. In some embodiments, lens housing 100 is less than or equal to one and one-half inches in diameter. In other embodiments, lens housing 100 is less than or equal to one inch in diameter. In still other embodiments, lens housing is less than or equal to one-half inch in diameter. In other embodiments, lens housing 100 is a head-mounted display form factor incorporating an eyepiece. In yet other embodiments, lens housing 100 is a low profile, lapel- or epaulet-mounted form factor. Other form factors for lens housing 100 are also possible.

Mounted inside lens housing 100 are lens assemblies 102 and 104. In some embodiments, additional lens assemblies may also be present. Each such lens assembly has an optical axis, defined as the ray passing through the center of the lens and oriented in the direction the lens assembly is pointed. Thus, the optical axis determines the field of view for the lens assembly. In one embodiment, lens assemblies 102 and 104 are fixedly mounted in lens housing 100 such that their optical axes are reciprocal. In another embodiment lens assemblies 102 and 104 are mounted in lens housing 100 such that their lens assemblies are skew. Such lens orientations are discussed in greater detail with respect to FIG. 4. In still another embodiment, one or both of lens assemblies 102 and 104 are rotatably mounted to lens housing such that their optical axes can be adjusted according to need. Such rotatable mounts may be freely rotatable in a plane or along two axes, and may have one or more detents determining preset positions.

Each of lens assemblies 102 and 104 is operable to provide a video feed of video data. While reference is made to “video data” and “video feeds,” In some embodiments, lens assemblies 102 and 104 may instead, or in addition, record still image data. In some such embodiments, one of lens assembly 102 and 104 will record video data and the other will record still image data.

In certain embodiments, lens housing 100 may also include a display 106. In some such embodiments, an actuator is included to switch display 106 between the available video feeds from lens assemblies 102, 104 or other lens assemblies or no feed. In some such embodiments, the actuator is mounted in lens housing 100, display 106, or battery housing 108. In some embodiments, display 106 may be a monocular display for displaying the video feed from lens assembly 102, lens assembly 104, or both. In other embodiments, display is a glassless holographic display. Where present, display 106 generally may be any form of image display technology now known or hereafter discovered invented. In some embodiments, display 106 is not integrated into lens housing 100, but rather removably attached, either directly or via a cable or wireless connection. In other embodiments, display is not connected to lens housing 100 directly, but rather via battery housing 108.

In some embodiments, lens housing 100 will also have an attachment point 110 for connecting to one of a variety of suitable mounts. This attachment point may be purely mechanical, or may incorporate data connections for connection to display 106, battery housing 108, and/or other peripheral units. Examples of such attachment points include screw mounts, clip mounts, ball-and-socket mounts, friction mounts, and snap mounts. Any type of mounting hardware, now known or hereafter discovered may be used.

In some embodiments, lens housing 100 is connected to battery housing 108 via cable 112. In some embodiments, cable 112 provides power to lens assemblies 102 and 104, and other components mounted in or attached to lens housing 100. In other embodiments, cable 112 incorporates unidirectional or bidirectional data connections between components mounted in or attached to lens housing 100 and components mounted in or attached to battery housing 108. In these embodiments, cable 112 is communicatively coupled to lens assemblies 102 and 104. In some such embodiments, cable 112 is further communicatively coupled to display 106. In some embodiments, cable 112 is not connected directly to lens housing 100, but rather indirectly via a mount connected to attachment point 110 or otherwise. In still other embodiments, communication between lens housing 100 and battery housing 108 is a wireless connection such as that provided by a personal-area network (PAN), and there is no physical connection between the two housings.

In some embodiments where it is present, cable 112 also connects to battery housing 108. In other embodiments, there may not be a separate battery housing 108, but rather all of the components described herein are mounted in lens housing 100. In other embodiments, some of the components described here as mounted in battery housing 108 are instead mounted in lens housing 100. Similar to lens housing 100, in some embodiments, battery housing 108 also has an attachment point 114. Attachment point 114 can take the form of a spring clip for attachment to clothing or a belt, or can be a universal connector that can attach to a variety of mounts. Other forms of attachment point 114 are also possible.

In some embodiments, power supply 116 is mounted in battery housing 108. In some embodiments, power supply 116 is a set of rechargeable battery cells. These cells can be removable for recharging or chargeable via an external connection. In other embodiments, power supply is one or more non-rechargeable batteries. In still other embodiments, power supply 116 is a fuel cell or micro-turbine. Any form of power supply, now known or hereafter invented may be used as power supply 116. It is an advantage of embodiments of the invention with separate lens housing 100 and battery housing 108 that the weight and volume consumed by power supply 116 is separated from lens housing 100, allowing lens housing to be more comfortably mounted on the user's body, such as in a head-mounted configuration. In some embodiments, power supply is electrically coupled to lens assemblies 102 and 104. In other assemblies, it is further electrically coupled to display 106. Power supply 116 may also be electrically coupled to other components mounted in battery housing 108. In some embodiments, separate power supplies may be provided for components in lens housing 100 and battery housing 108.

In some embodiments, battery housing 108 also contains controller circuitry 118. In various embodiments, controller circuitry 118 performs different functions associated with the operation of the camera unit including video encoding, trigger event detection, storage management, and input/output (I/O) control, as well as other functions known in the art. Controller circuitry 118 may take the form of a microcontroller, microprocessor, or special-purpose controller circuitry. Controller circuitry 118 may also incorporate one or more computer-readable media for storing device firmware. Controller circuitry 118 is electrically coupled to power source 116, and communicatively coupled to lens assemblies 102 and 104 as well as various components installed in battery housing 108, including storage memories such as volatile memory 120 and non-volatile memory 122, sensors such as sensor 124, and I/O ports and controllers such as I/O unit 126. One exemplary method of operation for controller circuitry 118 is depicted in FIG. 5.

Encoded video data and other data processed by controller circuitry 118 may be stored in one or more memories such as volatile memory 120 or non-volatile memory 122. In one embodiment, video is recorded continuously, along with any relevant metadata, and stored in volatile memory 120. When a triggering event occurs, the contents of volatile memory 120 are transferred to non-volatile memory 122, and incoming video is also stored in non-volatile memory. In other embodiments, two non-volatile or volatile memories are used. In yet other embodiments, a single memory is used. In some single-memory embodiments, all video data is stored to non-volatile memory 122. In other single-memory embodiments, a triggering event initiated the recording and storage of data. In some embodiments, non-volatile memory 122, volatile memory 120, or both provide authenticated, tamper-resistant storage such that recorded data can be used as evidence in legal proceedings. In some embodiments, controller circuitry 118 uses a device-specific key to digitally sign or otherwise authenticate video recordings. In some embodiments, non-volatile memory 122 is a removable memory card. In some such embodiments, non-volatile memory is write-once, read-many (WORM) memory. In general, the storage memories used in embodiments of the invention can be any data storage media known in the art as described herein or invented in the future. In some embodiments, battery housing 108 has no persistent storage memory, and video data that is to be retained is transmitted in real time over a network to a remote data store. In other embodiments, data to be retained is both stored locally and transmitted to a remote data store.

In some embodiments, additional sensors such as sensor 124 are present in battery housing 108, lens housing 100, or elsewhere. Such sensors may provide data to supplement the video data provided by lens assemblies 102 and 104. Examples of such sensors include a microphone for recording audio data, a radio receiver for recording radio transmissions, a global-positioning system (GPS) receiver for recording position data, one or more accelerometers for recording movement and acceleration data, and a radio-frequency identifier (RFID) receiver for recording the presence of nearby RFID tags such as RFID tag 128 in other units. RFID tag 128 can, in turn, be read by sensors present in other camera units, or by readers in an associated system such as a unit mounted in a patrol car. Such associated systems may also have their own RFID tags. Although the above discussion references RFID tags and readers, any wireless signaling mechanism can be used to similar effect. Additional sensors, such as a holster event sensor, may be directly or wirelessly connected. Sensor 124 may include or take the form of other sensors and transceivers now known or hereafter invented.

In some embodiments, battery housing 108 or lens housing 100 may also contain an I/O unit such as I/O unit 126. Such an I/O unit may allow additional modules such as those containing additional sensors to be attached. In some embodiments, I/O unit allows data from storage memories 120 and 122 to be transferred off of the device. In other embodiments, it allows controller circuitry 118 to be reprogrammed. In yet other embodiments, it allows power supply 116 to be recharged. It will be apparent to a person skilled in the art that I/O unit 126 may perform all of these functions, individually or in parallel.

Turning now to FIG. 2, two views of one embodiment of the lens housing are presented. FIG. 2(a) presents a front-right perspective view. As depicted, lens housing 100 is comprised of forward lens housing 10 and rear lens housing 12. Forward lens housing 10 contains forward lens assembly 14, corresponding to first lens assembly 102 in FIG. 1. Similarly, rear lens housing 12 contains rear lens assembly 16, corresponding to second lens assembly 104 in FIG. 1. In this embodiment, forward lens housing 10 and rear lens housing 12 are fixedly attached such that forward lens assembly 14 and rear lens assembly 16 are oriented such that they have reciprocal optical axes. In one embodiment, forward lens housing 10 and rear lens housing 12 are formed into a single integral unit. In another embodiment, they are formed separately but permanently attached. In still another embodiment, rear lens assembly 12 is removeably attached to front assembly 10. In some such embodiments, modular assemblies may be used such that front lens assembly 14 and/or rear lens assembly 16 can be substituted with a wide-angle or zoom lens as the occasion requires. FIG. 2(b) shows a rear-right perspective view of this embodiment, further illustrating the arrangement of the above-described components. FIG. 2(b) further depicts mounting clip 18, corresponding to attachment point 110 in FIG. 1. Here, mounting clip 18 is suitably positioned for attachment to the right side of the user's head or body. Mounting clip 18 allows lens housing 100 to be attached to a wide variety of interchangeable mounts. Examples of such mounts include an earpiece, a headband, a hat clip, a shoulder clip, an epaulet mount, an eyeglass mount, and a collar mount. In general, mounts can include, but are not limited to, any way of attaching lens housing 100 to the user's body.

Also shown is port 20, which, in this embodiment, accepts cable 112. It is an advantage of this embodiment of the invention that the separation between lens housing 100 and battery housing 108 allows the depicted battery housing to be much smaller and more compact than is possible with single unit with all of the components depicted in lens housing 100 and battery housing 108 mounted in a single housing. As shown, lens housing 100 is less than two inches in length and one-half inch in diameter.

Turning now to FIG. 3, three views of an alternate embodiment of the lens housing are presented. FIG. 3(a) depicts a front-right perspective view corresponding to FIG. 2(a). In this embodiment, forward lens housing 10 and rear lens housing 12, rather than being an integral unit, are rotatably attached by pivot 22. Pivot 22 rotates around an axis normal to the ground and defines the common plane of the respective optical axes of front lens assembly 14 and rear lens assembly 16. FIG. 3(b), corresponding to the right-rear perspective view of FIG. 2(b), further depicts the arrangements of the rotatable rear lens housing. As discussed above, rear lens housing 12 may be freely rotatable or pivot 22 may have a number of detents corresponding to preselected angles. For example, detents may be included for positions of rear lens housing 12 such that rear lens assembly 16 is angled 90°, 180°, or 270° from front lens assembly 14. In another embodiment, detents additionally be included corresponding to angles or 45°, 135°, 225° and 315°. In another embodiment, pivot 22 is a friction pivot such that rear lens assembly can be adjusted such that rear lens assembly 16 and front lens assembly 14 form any angle. In still another embodiment, pivot 22 is a screw-type pivot such that it can be loosened, the angle between rear lens assembly 16 and front lens assembly 14 adjusted, and re-tightened such that the angle remains fixed. In yet another embodiment, both front lens housing 10 and rear lens housing 12 rotate around pivot 22 such that they can be independently oriented. FIG. 3(c) depicts an overhead view of this embodiment, more clearly illustrating the skew orientation of the respective optical axes of front lens assembly 14 and rear lens assembly 16. It is an advantage of this embodiment that the skew angle can be adjusted by rotating rear lens housing 12 about pivot 22.

Turning now to FIG. 4, three representative orientations of lens assemblies are presented. FIG. 4(a) depicts a parallel orientation of the optical axes of two lens assemblies. Such orientations are also referred to as “paraxial.” While paraxial lens assemblies do not provide a notably larger field of view than that provided by a single lens assembly, the distance between the lens assemblies can provide parallax and therefore depth information. FIG. 4(b) depicts reciprocal optical axes. Such a lens arrangement has the advantage of providing the largest possible field of view, but, depending on the particular lens assemblies, has a blind spot near the lens assemblies themselves. For example, in a head-mounted configuration, there may be no coverage of the area immediately behind the user's back. FIG. 4(c) depicts skew reciprocal axes. As used herein, skew axes refer to an orientation that is neither parallel nor reciprocal without regard to whether the axes are coplanar. A skew orientation of optical axes can have several advantages, particularly when the angle between the axes is adjustable. For example, in a head-mounted configuration, one lens can be angled to cover the user's back while on foot, and adjusted to cover the view out a side window while driving.

Turning now to FIG. 5, an exemplary method suitable for use with one embodiment of the camera unit is depicted. The method begins at step 500 when the unit powers on. At this point, controller circuitry such as controller circuitry 118 begins receiving data signals from the lens assemblies such as lens assembly 102 and lens assembly 104. This data is combined with any data from supplementary sensors such as sensor 124 and encoded in real time as is known in the art. At step 502, this data is stored in volatile memory 120 until volatile memory 120 is full, at which point writing begins again at the beginning of volatile memory 120, progressively overwriting the oldest data in the manner of a circular buffer. In this manner a continuous recording of all data is maintained for a period of time proportional to the size of volatile memory 120 and inversely proportional to the rate at which encoded data is generated. As a person skilled in the art will appreciate, non-volatile memory may also be used in the place of volatile memory 120.

Next, at step 504, a triggering event is detected. Such triggering event can be any event suggesting that a record of the immediately preceding and/or succeeding events should be retained. A first class of triggering events relates to circumstances around the user. For example, the user triggering the siren and/or light bar of a patrol cruiser might be a triggering event. Alternately, a velocity or acceleration reading, either from the cruiser or from integrated velocity and/or sensors such as sensor 124 may be a triggering event. For example, a velocity of the user wearing the housing 100 may be a triggering event, such as the user running as opposed to walking. Similarly, a vehicle crash, detected by an accelerometer reading, airbag deployment, or similar stimulus, might be a trigger event. Additionally, a positional reading could be a triggering event. Such a positional reading could be absolute (for example, entering or exiting a particular geo-fenced area) or relative (for example, moving more than a particular distance from a patrol cruiser or other fixed or mobile point of reference).

Such a sensor-related triggering event may be generated directly by the sensor, or by a recording device manager, such as a Digital Ally® VuLink®, that controls and synchronizes various recording devices. For example, the recording device manager may communicate (via wireless communication, wired communication, or both) to sensors such as described herein, one or more person-mounted camera units, a vehicle-mounted video camera oriented to observe events external to the vehicle, a vehicle-mounted video camera oriented to observe events internal to the vehicle, and/or one or more storage storage elements. In some embodiments, the recording device manager detects when one video camera begins recording, and then instructs all other associated devices to begin recording. The recording device manager may also send information indicative of a time stamp to the various recording devices for corroborating the recorded data.

For example, the recording device manager may instruct all associated video cameras to begin recording upon the receipt of a signal from a sensor such as a breath analyzer that a breath analysis has begun. This ensures that multiple video cameras record the breath analysis, for future authentication that the breath analysis was performed correctly. The recording device manager may also send a time stamp to all the associated video cameras to provide a corroboration of the various recorded data.

A second class of triggering events relates to the user. For example, a sensor configured to detect when a holster cover is opened or when a weapon is removed from the holster could generate a triggering event. Another form of user-related triggering event could come in the form of one or more biometric stress indications (such as elevated heart rate, blood pressure respiration, etc.) obtained from biometric sensors worn by the user. Similarly, audio data could generate triggering events if raised voices or high levels of vocal stress are detected.

A third class of triggering events relates to context recognition from the data being collected. For example, when controller circuitry 118 detects that the video data it is processing contains a face, a triggering event could be generated. Alternately, this functionality could be limited to the recognition of a particular face (for example, if the user sees a face matching a photograph provided with a warrant, or on a wanted poster, a trigger event could be generated). Such triggering events can, in some embodiments, be limited to a particular video stream. For example, face detection could only act as a triggering event when the rear camera detects the face; i.e., when a person approaches the user from behind. Similar recognition algorithms can be applied to other data streams as well; for example, the audio signature of a gunshot could be a triggering event, or the positional signature of evasive maneuvering.

Finally, a triggering signal can be generated manually by the user or, in embodiments where data is streamed to a remote date store, by a remote observer. Of course, a person of skill in the art will recognize that a wide variety of triggering signals are possible and variations and combinations of the above will be apparent.

In response to the triggering signal, at step 506, controller circuitry 118 copies the contents of volatile memory 120 to non-volatile memory 122. In this way, a permanent record is created of not merely events following the trigger signal, but of those preceding it was well. This transfer process continues at step 508 as new data is stored to volatile memory 120, in effect recording the live data to non-volatile memory 122 as well. In some embodiments, after a trigger signal is detected, data is recorded directly to the non-volatile memory instead of indirectly via the volatile memory.

Finally, at step 510, the trigger event ends. How this occurs will vary in different embodiments and with different trigger events. In some embodiments, recording to non-volatile memory 122 will continue until the end of shift for the user. In other embodiments, it will continue until non-volatile memory 122 is full. In still other embodiments it will continue until the camera unit is powered down, or until the user manually deactivates it. Additionally, some trigger events can terminate on their own. For example, if the user leaving their patrol car is a trigger event, then returning to the car may end the triggering event, either immediately or after some predetermined delay. Similarly, if elevated biometric readings generate a trigger event, then a return to normal levels may terminate, perhaps with a delay or some level of hysteresis. In some embodiments, the user may be able to manually cancel a trigger event, while in other embodiments this may be undesirable. At this point, processing returns to step 502 to await further trigger signals.

Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the scope of the claims below. Embodiments of the invention have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to readers of this disclosure after and because of reading it. Alternative means of implementing the aforementioned can be completed without departing from the scope of the claims below. Certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Although the invention has been described with reference to the embodiments illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims. 

Having thus described various embodiments of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following:
 1. A camera unit: a first lens assembly having a first optical axis; a second lens assembly having a second optical axis being different than and generally opposed to the first optical axis; a housing containing both the first lens assembly and the second lens assembly, wherein the second lens assembly is permanently and rotatably mounted such that the second optical axis is configured to allow manual rotation relative to the first optical axis, wherein the manual rotation is about an axis perpendicular to the first optical axis; a memory element for storing recorded video data from both the first lens assembly and the second lens assembly, wherein the storing the recorded video data is performed by storing pre-event buffer data, wherein the pre-event buffer data includes the recorded video data without audio data; wherein an instruction to record causes recording the audio data; and a controller configured to receive video data from the first lens assembly and the second lens assembly and store the video data and a timestamp as metadata for synchronizing the video data; receive an indication that an external camera has received the instruction to record; receive an identifier associated with the external camera; write the identifier as metadata associated with the video data; and upload the recorded video data to an external computing device, wherein the identifier allows the recorded data to be subsequently linked with video data from the external camera.
 2. The camera unit of claim 1, wherein the first optical axis is configured to be oriented toward an interior of a law enforcement vehicle, wherein the second optical axis is configured to be generally outward from the law enforcement vehicle.
 3. The camera unit of claim 1, wherein the instruction to record is automatically triggered by a triggering event.
 4. The camera unit of claim 1, wherein the controller is further configured to instruct recording to begin upon said receiving of the indication that the external camera has received an instruction to record.
 5. The camera unit of claim 1, wherein the camera unit is a vehicle recording device operable to record video data and audio data, wherein the vehicle recording device is operable to be mounted in a law enforcement vehicle.
 6. The camera unit of claim 1, wherein the camera unit is a personal recording device operable to record video data and audio data, wherein the personal recording device is operable to be worn by a law enforcement officer.
 7. The camera unit of claim 1, wherein the camera unit is an infrared camera.
 8. The camera unit of claim 1, wherein the identifier is a unique serial number that is indicative of an unalterable serial number of the external camera.
 9. The camera unit of claim 1, wherein the external camera stores a second identifier associated with the camera unit in video data recorded by the external camera.
 10. The camera unit of claim 1, wherein the external computing device is a smartphone carried by a law enforcement officer, wherein the smartphone is configured to display the recorded data.
 11. The camera unit of claim 1, wherein the controller is configured to send a signal indicative that recording has begun.
 12. The camera unit of claim 1, wherein the external camera is within a certain range of the camera unit when said indication that an external camera has received an instruction to record is received.
 13. The camera unit of claim 1, wherein the controller is further configured to: store a location indication where the data was recorded in metadata; and continue to record until receiving an instruction to stop recording from a law enforcement officer.
 14. A system comprising: a first camera unit; and a second camera unit including a first lens assembly having a first optical axis; a second lens assembly having a second optical axis being different than and generally opposed to the first optical axis; a housing containing both the first lens assembly and the second lens assembly, wherein the second lens assembly is permanently and rotatably mounted such that the second optical axis is configured to allow manual rotation relative to the first optical axis, wherein the manual rotation is about an axis perpendicular to the first optical axis; a memory element for storing video data both the first lens assembly and the second lens assembly; and a controller configured to receive video data from the first lens assembly and the second lens assembly and store the video data and a timestamp as metadata for synchronizing the video data, wherein the storing the video data is performed by storing pre-event buffer data, wherein the pre-event buffer data includes the video data without audio data; wherein moving to a recording status begins recording the audio data; receive an indication that the first camera unit has received an instruction to record; receive an identifier associated with the external second camera unit; write the identifier as metadata associated with the recorded data; and upload the recorded video data to an external computing device, wherein the identifier allows the recorded data to be subsequently linked with video data from the external second camera unit.
 15. The system of claim 14, wherein the second camera unit is a vehicle recording device operable to record video data and audio data, wherein the vehicle recording device is operable to be mounted in a law enforcement vehicle, wherein the first camera unit is a personal recording device operable to record video data and audio data, wherein the personal recording device is operable to be worn by a law enforcement officer.
 16. The system of claim 14, wherein the external camera is within a certain range of the second camera unit wherein the controller is configured to send a signal indicative that recording has begun.
 17. A system comprising: a first camera unit; and a second camera unit including a first lens assembly having a first optical axis; a second lens assembly having a second optical axis being different than and generally opposed to the first optical axis; a housing containing both the first lens assembly and the second lens assembly, wherein the second lens assembly is permanently and rotatably mounted such that the second optical axis is configured to allow manual rotation relative to the first optical axis, wherein the manual rotation is about an axis perpendicular to the first optical axis; a memory element for storing video data both the first lens assembly and the second lens assembly; and a controller configured to receive video data from the first lens assembly and the second lens assembly and store the video data and a timestamp as metadata for synchronizing the video data, wherein the storing the video data is performed by storing pre-event buffer data, wherein the pre-event buffer data includes the video data without audio data, wherein moving to a recording status begins recording the audio data; wherein the first camera unit is within a certain range of the second camera unit; receive an identifier associated with the first camera unit; send a signal indicative that recording has begun; write the identifier as metadata associated with the recorded data; and upload the recorded video data to an external computing device, wherein the identifier allows the recorded data to be subsequently linked with video data from the external camera. 